High -and Moderate-intensity resistance training provokes different effects on body composition, functionality, and well-being in elderly

Purpose: To compare the short-term effects of a resistance training program with elastic bands at moderate and high intensity on the body composition, functional capacity, and well-being of overweight and obese older women. Method: 75 women (68.7 ± 4.7 years) were assigned to a control group (n = 25) or to one of two treatment groups: (i) high intensity (G6 = 6 repetitions, n = 25) and (ii) moderate intensity (G15 = 15 repetitions, n = 25). Body composition (fat and fat-free mass), functional capacity (isometric strength; 30-s-arm-curl, 30-s-chair-stand, timed up & go test, and 6-min-walk-test [6MWT]), and well-being were evaluated before and after 8 weeks of intervention by using the 36-Item-Short-Form-Survey (SF-36). Results: 61 participants completed the study. The G15 group generated greater positive changes in the percentages of total and segmental fat mass (≃2.8%, p ≤ .05) and better performance in the 6MWT than the other groups. The G6 group showed greater improvements in the timed up & go and muscle strength tests than the G15 group. The G6 and G15 groups showed significant improvements in the following sections of SF-36: general health perceptions, physical functioning, mental health, and vitality. The performance of all variables worsened in the control group. Conclusions: The 8 weeks of intervention caused positive and significant changes in all study variables, although the results confirmed that this duration is insufficient to generate clear differences according to the level of exercise intensity. Nevertheless, G15 caused greater improvements in the percentage of fat mass and in aerobic resistance, whereas G6 improved the lower-limb muscle strength.